Switched inductor DC-DC power converters such as buck converters provide conversion of power from a high voltage potential to a low voltage potential. These types of converters are used in a broad and diverse set of applications. One typical application is the conversion and regulation of power supplies for microprocessors and other sensitive or high-performance integrated circuits.
In current microelectronic systems, the components of the power converter (e.g., power control integrated circuit, power switches, inductor(s), and capacitors) are mounted on a circuit board at a significant lateral and vertical distance from the processor, which consumes the power output from the power converter. This large distance results in significant power loss due to thermal conduction loss (P=I2R loss) in the interconnect that transfers electrical current to the processor chip from the power converter on the circuit board. Additional power loss is caused by the large AC impedance that typically exists in the interconnect from circuit board to the processor chip or die because dynamic changes in processor current consumption will cause significant supply voltage deviations, which necessitate inefficient supply voltage margins to ensure that the supply does not fall below a minimum required voltage potential for correct operation of the processor chip. For example, “if the minimum supply voltage for correct operation of a processor is 0.7 V, but a “worst-case” load-current transient can induce a transient error on the supply voltage of 100 mV across the impedance of the power delivery interconnect, then it is necessary to supply the processor chip with >0.8 V to ensure that, in the event of a “worst-case” load-current transient, the supply voltage does not fall below 0.7 V. This supply voltage margin results in greater than 15% additional power consumption for the processor chip. An example of such a known system is illustrated in FIG. 1.
Some attempts have been made to integrate the power converter onto the processor package substrate. In doing so, the resistance and AC impedance of the electrical interconnect between the power supply regulator and processor chip is reduced, allowing for reductions in thermal conduction loss and supply voltage margin loss. However, such attempts have been unable to realize efficient power converter implementations that are small enough to be integrated in the processor package, and often incur additional performance or functionality compromises for the system, such as the removal of electrical terminals from the processor package substrate, which reduces data bandwidth to/from the processor.
It would be desirable to overcome one or more of these and other deficiencies in the art.